1. Field of the Invention
The present invention relates to demodulators. More particularly, this invention pertains to a synchronous demodulation system that provides a digital output.
2. Background of the Prior Art
The need to demodulate a measurement signal (e.g. a signal of higher frequency) over a relatively broad dynamic range such as five or seven decades often arises in instrumentation and control engineering. An example of a measurement signal having a large dynamic range is that provided by a fiber optic gyroscope, the output of which must be measured with great accuracy over a very large dynamic range with respect to the amplitudes of one or more frequency components.
Known synchronous demodulators and analog/digital converters (A/D converters) often experience difficulties as a result of the fact that on the one hand, they do not operate linearly at relatively high signal amplitudes while, on the other hand, their zero stabilities are inadequate at very low signals.